Asthma is a chronic inflammatory disease of the lungs that is influenced by a combination of host susceptibility and environmental exposures. Particulate air pollution is a pro-inflammatory agent that has been associated with adverse health consequences. While much research has focused on outdoor exposures, the indoor environment is critical as Americans spend most of their time indoors and the investigators' preliminary data have demonstrated that indoor PM concentrations greatly exceed outdoor PM concentrations in urban homes. Based on preliminary data that suggest a strong association between coarse PM exposure and respiratory symptoms among those with non-allergic asthma, the investigators hypothesize that exposure to indoor coarse PM promotes inflammation and worsening of respiratory symptoms and lung function among individuals with non-allergic asthma. Using a study design that combines a longitudinal panel study and an exposure challenge model, the investigators will aim to provide evidence of a causal relationship between indoor coarse PM exposure and exacerbation of asthma status. In specific aim 1, they will determine the effect of indoor coarse PM exposure on asthma health by conducting an epidemiologic panel study measuring in-home PM concentrations and corresponding daily variation in lung function, asthma symptoms, and biomarkers of inflammation among inner-city minority children with non-allergic asthma. In specific aim 2, they will investigate the short-term effects of coarse PM exposure on non-allergic asthma by administering a controlled, nebulized PM challenge and measuring airway reactivity and biomarkers of inflammation. Completion of the proposed research, along with complementary training and mentorship in an outstanding and supportive environment for clinical research, will provide in-depth exposure to clinical research design, conduct, and analysis. These experiences will allow the principal investigator to become a successful, independent investigator in academic medicine. Asthma affects more than 20 million individuals in the U.S, including over 6 million children and young adults. The proposed research investigates the effect of an environmental exposure, air pollution, on this disease process. If indoor exposure to airborne PM triggers asthma exacerbations and stimulates an inflammatory response, the findings from this study may direct new therapeutic interventions and will represent an important advancement in the treatment of asthma with profound public policy implications.